Fast analysis of phthalates in freeze-dried baby foods by ultrasound-vortex-assisted liquid-liquid microextraction coupled with GC-IT/MS

This paper is focused on the determination of phthalates (PAEs), compounds “plausibly” endocrine dis- ruptors, in baby food products by means of a method based on ultrasound-vortex-assisted liquid-liquid microextraction coupled with GC-IT/MS (UVALLME-GC-IT/MS). Particularly, the whole procedure allows the determination of six phthalates such as DMP, DEP, DBP, iBcEP, BBP and DEHP. After dissolution of 0.1 g product sample and addition of anthracene as Internal Standard, 250 L of n-heptane are used as extraction solvent. The solution, held for 5 min on the vortex mixer and for 6 min in an ultrasonic bath at 100 W for favoring the solvent dispersion and consequently the analyte extraction, is centrifuged at 4000 rpm for 30 min. About 100 L of heptane are recovered and 1 L is injected into the GC-IT/MS. All the analytical parameters investigated are deeply discussed: under the best conditions, the percentage recoveries range between 96.2 and 109.2% with an RSD ≤10.5% whereas the Limit of Detections (LODs) and the Limit of Quantifications (LOQs) are below 11 and 20 ng g−1 , respectively, for all the PAEs except for iBcEP (23 and 43 ng g−1 , respectively). The linear dynamic range of this procedure is between 10 and 5000 ng g−1 with R2 ≥0.92. The method has been applied to real commercial freeze-dried samples (chicken and turkey meats) available on the Italian pharmaceutical market: three PAEs were preliminary identified, i.e. DEP (14 ng g−1 ), DBP (11 ng g−1 ) and DEHP (64 ng g−1 ).